Rybakina's first match as world number one ends in defeat

Three-times Grand Slam champion Elena Rybakina crashed out of the China Open with a shock 3-6 6-4 6-3 defeat by unseeded Alina Charaeva in the second round on Saturday, marking a disappointing start to her reign as world number one.

The 27-year-old was playing for the first time since defeating four-times major winner Aryna Sabalenka to capture the US Open title last month.

Rybakina had skipped Kazakhstan's Billie Jean King Cup Finals campaign after what she described as a physically demanding month.

Charaeva, a 24-year-old Russian-born Armenian ranked 118th in the world, etched her name into the record books by becoming the lowest-ranked competitor since the introduction of the WTA rankings in 1975 to rally from a set down to defeat the world's top ranked player.

Having weathered Rybakina's early charge, Charaeva converted five of eight break-point opportunities and won 76 per cent of points behind her first serve.

Rybakina struggled on serve, committing seven double faults in the two-hour, 11-minute contest at the WTA 1000 hardcourt event.

Charaeva will next meet Britain's Sonay Kartal.

In the men's draw, German top seed Alexander Zverev swept aside local hope Shang Juncheng 6-0 6-3 in the round of 16.

Fresh from his US Open triumph and helping Team Europe win the Laver Cup, Zverev will next take on 24-times Grand Slam champion Novak Djokovic in Sunday's quarter-final.

The 39-year-old Serb boasts a perfect 31-0 record at the ATP 500 event and holds the tournament record with six China Open titles.